The invention concerns a knitting machine of the kind defined in the generic part of claim 1.
In knitting machines of this kind (e.g., German OS Nos. 2,531,705, 2,531,734 and 2,531,762, the rails controlling the cam units are usually provided above the butts or projections of the knitting tools, and are intended to act upon lowering means resiliently disposed on the cam units for the purpose of displacing them during the movement of the cam units past the knitting tools to such a position relative to the needle bed that the knitting tools are lowered by the amount called for by the pattern for the formation of the stitches.
Since it can be desirable for reasons of pattern to adjust succeeding lowering means to a variety of different lowering or coulier depths, it is already known (German OS No. 2,531,705) to provide above each needle bed a group of rails which are adjustable in level in accordance with the desired lowering depth, and to provide on each lowering means or carrier thereof a number of grooves corresponding to the number of pathways into which the runners in the form of plates can be inserted in order to associate each lowering means with a selected pathway. Such devices, however, are not suitable for a variation of the lowering depth while the knitting machine is in operation.
To make it possible to adjust the lowering means with the knitting machine running, it is furthermore already known (German OS NO. 2,531,705) to provide controllable actuators disposed outside of the needle beds for the preadjustment of each lowering means or means for the adjustment of the lowering means cooperating with shims of different thickness. Apparatus of this kind are relatively complex and therefore liable to trouble, and either they increase the amount of space required for the knitting machine or they interfere with access to the stitch-forming parts thereof.
It is the aim of the invention, therefore, to improve a knitting machine of the kind described above such that the setting of the lowering depth of each individual lowering means before it moves past the knitting tools can be accomplished by simple means and by a simple method of operation.
To achieve the aim, the specific features of claim 1 are provided.
The invention offers the advantage that the setting of the lowering depth of each lowering means can be accomplished before it runs past the knitting tools by the mere operation of the actuator. It is therefore necessary neither to deliver control signals to moving parts such as the cam units, for example, nor to stop these parts momentarily during the operation of the knitting machine for the purpose of adjusting the lowering depth. In addition, the actuator can in accordance with the invention consist of a simple arrangement of switches which deliver the runners, prior to each movement of the lowering elements past the knitting tools, to the pathway which is required according to the pattern for the adjustment of the lowering depth.
Additional advantageous features of the invention are specified in the subordinate claims.